HIKE OF THE MONTH

{hike of the month} The Other Painted Desert Trail to the West Traverses Special Geology

ARIZONA HAS TWO painted deserts-the official one between the Grand Canyon and the Petrified Forest National Park and the largely undiscovered one tucked away in the Imperial National Wildlife Refuge along the lower Colorado River. Lots of people oooh and ahhh at the official painted desert-but the pigmented hoodoos, hills and hollows along the lower Colorado remain a largely undiscovered geological art treasure. Fortunately, the Imperial refuge's Painted Desert Trail takes hikers on a relatively easy, 1.3-mile loop through geology as colorful and curiously eroded as anything you'll find in its better known sibling landscape. Despite the similar color pallets, these two deserts have created their chromatic masterpieces using different geological mediums. The famous Painted Desert around Holbrook is made of layers of sedimentary rock, weathered and rusted into warm reds, oranges, pinks and blues. But the Colorado River version acquired its unique geology by way of ash sprayed from volcanoes some 30 million years ago, scientists say. Multihued minerals colored the cooling rock-iron for the reds, copper for the greens, and aluminum for the pinks and purples. Wind, water and weather then carved the details.

The short Painted Desert Trail heads away from the river into a dry desert landscape that sees, at best, only 3.5 inches of rain each year. A handful of prickly pear cacti, ironwood and mesquite trees and brittlebushes offers a beleaguered token of vegetation.

However, if enough winter rain falls, wildflowers miraculously cover the gravelly slopes. In February, the trail comes alive with migrating monarch butterflies traveling north from the mountains of Mexico. The monarchs head right for the yard-high milkweed plants that in spring grow along the trail. The butterflies live mostly on the milkweed's flowers, concentrating the plant's defensive chemicals to give themselves a bitter taste that repels most predators. The monarchs sometimes get so thick along the trail they land on hikers, especially those who look at all like milkweed.

With or without a show of butterflies or wildflowers, geology remains the trail's main attraction. During the first half-mile, the trail wends around ruddy mounds, passes A distinct hoodoo and then climbs a little hill that gives big views. Colorful ash mounds spread to the west. A bit farther westward, a sliver of the Colorado River shimmers.

A ridge full of buttes rises in the east. Made of hard, "volcanic plugs" stuck in the throats of vanished volcanoes and vents, the bizarreformations resist the erosion that removes the surrounding, softer ridgeline.

After another short climb, the path twists back down to the desert floor and enters Shady Canyon Wash. Animal signs and tracks show that this shaded segment makes a cool hangout for reptiles and mammals. Finally, an odd but beautiful assortment of colored mounds closes the loop. So don't be satisfied with just one Painted Desert, all crumbly, soft and printed out on the map. You don't have to be a butterfly to appreciate an exotic splash of color in a strange and twisted landscape. Al